Capturing images under varying lighting conditions

Abstract

An image capture device using an image sensor having color and panchromatic pixels and structured to permit the capture of a color scene image under different lighting conditions.

1 . A method for capturing a scene image under varying lighting conditions, comprising: 
 a) providing an image sensor having panchromatic and color pixels;    b) a user selecting a scene mode and adjusting the image capture exposure as a function of lighting conditions and the selected scene mode; and    c) capturing a scene by the image sensor using the adjusted exposure.    
   
   
       2 . The method of  claim 1  further including: 
 d) providing from the captured image a digital panchromatic image and an intermediate digital color image; and    e) using the digital panchromatic image and the intermediate digital color image to provide the final digital color image.    
   
   
       3 . The method of  claim 1  wherein the image capture exposure is automatically controlled.  
   
   
       4 . The method of  claim 1  wherein the image capture exposure is manually controlled.  
   
   
       5 . A method for capturing a scene image under varying lighting conditions, comprising 
 a) providing an image sensor having a two-dimensional array of pixels including first and second groups of pixels with pixels from the first group of pixels having narrower spectral photoresponses than pixels from the second group of pixels and with the first group of pixels having individual pixels  30  that have spectral photoresponses that correspond to a set of at least two colors, wherein the placement of the first and second groups of pixels defines a pattern that has a minimal repeating unit including at least twelve pixels, the minimal repeating unit having a plurality of cells wherein each cell has at least two pixels representing a specific color selected from the first group of pixels and a plurality of pixels selected from the second group of pixels arranged to permit the reproduction of a captured color image under different lighting conditions;    b) a user selecting a preferred scene mode and adjusting the image capture exposure as a function of lighting conditions and the selected scene mode; and    c) capturing a scene by the image sensor using the adjusted exposure.    
   
   
       6 . The method of  claim 5  further including: 
 d) providing from the captured image a digital panchromatic image and an intermediate digital color image; and    e) using the digital panchromatic image and the intermediate digital color image to provide the final digital color image.    
   
   
       7 . The method of  claim 5  wherein the image capture exposure is automatically controlled.  
   
   
       8 . The method of  claim 5  wherein the image capture exposure is manually controlled.  
   
   
       9 . The method of  claim 5 , wherein the image sensor is a charge coupled device or an active pixel sensor.  
   
   
       10 . A method for capturing a scene image under varying lighting conditions, comprising 
 a) providing an image sensor having a two-dimensional array of pixels including first and second groups of pixels with pixels from the first group of pixels having narrower spectral photoresponses than pixels from the second group of pixels and with the first group of pixels having individual pixels that have spectral photoresponses that correspond to a set of at least two colors, wherein the placement of the first and second groups of pixels defines a pattern that has a minimal repeating unit including at least twelve pixels, the minimal repeating unit having a plurality of cells wherein each cell has at least two pixels representing a specific color selected from the first group of pixels and a plurality of pixels selected from the second group of pixels arranged to permit the reproduction of a captured color image under different lighting conditions;    b) receiving light from the scene and focusing such received light along an optical path onto the image sensor;    c) producing a signal representative of scene light intensity; and    d) adjusting the exposure of the image sensor in response to the signal.    
   
   
       11 . The method of  claim 10 , wherein the image sensor is a charge coupled device or an active pixel sensor.  
   
   
       12 . The method of  claim 10 , wherein step d) includes positioning at least one neutral density filter in the optical path when the scene light intensity is above a predetermined level for limiting the amount of light focused onto the sensor.  
   
   
       13 . The method of  claim 10 , wherein step d) includes positioning at least one color balance filter in the optical path.  
   
   
       14 . The method of  claim 10 , wherein step d) includes varying the aperture of the image capture device to change the light exposure on the image sensor.  
   
   
       15 . The method of  claim 10 , wherein step d) includes varying the integration time of image sensor pixels to change the light exposure on the image sensor.  
   
   
       16 . The method of  claim 15 , further including a mechanical shutter to control the integration time of the pixels in the image sensor.  
   
   
       17 . The method of  claim 15 , further including a timing generator to electronically control the integration time of the pixels in the image sensor.  
   
   
       18 . The method of  claim 10 , wherein step d) includes varying the integration time of image sensor pixels to provide at least two separate integration times for different pixels.  
   
   
       19 . The method of  claim 18  wherein the integration time of the either the first group or the second group of pixels is changed relative to the other group.  
   
   
       20 . The method of  claim 18  wherein the integration time of pixels of each color within the first group of pixels is changed relative to the integration time(s) of pixels of the other color(s).  
   
   
       21 . A method for capturing a scene under varying lighting conditions a scene in either single image capture or image stream capture, comprising: 
 a) providing an image sensor effective in a first condition for capturing a single image of a scene and, in a second condition, for capturing a stream of images from the scene, the image sensor having a two-dimensional array of pixels including first and second groups of pixels with pixels from the first group of pixels having narrower spectral photoresponses than pixels from the second group of pixels and with the first group of pixels having individual pixels that have spectral photoresponses that correspond to a set of at least two colors, wherein the placement of the first and second groups of pixels defines a pattern that has a minimal repeating unit including at least twelve pixels, the minimal repeating unit having a plurality of cells wherein each cell has at least two pixels representing a specific color selected from the first group of pixels and a plurality of pixels selected from the second group of pixels arranged to permit the reproduction of a captured color image under different lighting conditions;    b) receiving light along a path from the scene and for focusing light from the scene onto the image sensor; and    c) a user selecting the image sensor to capture a single image or to capture a stream of images.